Nixdorf System 820

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Systems of the Nixdorf 820 belonged to a model family that from 1965 on for Pulse Technology Laboratory (LFI), the predecessor company of Nixdorf Computer were (NCAG) developed. Initially, the LFI only acted as a supplier; The computers were sold under the name Logatronic by Wanderer-Werke . From around 1968 Nixdorf Computer took over the marketing itself.

Three product phases - booking machine, magnetic account computer and terminal systems - can be identified. The system appeared from 1967 to 1979 and was sold over 40,000 times in various model variants. The system was used, for example, for wage and salary accounting and invoicing. In addition, the computer (as the 820P) was also used successfully for process automation and control, e.g. B. for automatic winding machines from the company Schlafhorst in Mönchengladbach .

history

With the laboratory for pulse technology founded by Heinz Nixdorf in Essen in 1952 , the computer pioneer realized the construction of an electronic computer. Initially, the company only acted as a supplier of electronic arithmetic units for office machine manufacturers such as Exacta Büromaschinen GmbH - from 1963 Wanderer-Werke - in Cologne and the Compagnie des Machines Bull in Paris . The computing systems developed in the 1950s were based on tube technology.

In 1965 the Wanderer Logatronic, which was designed using transistor technology with the help of Otto Müller , came onto the market. This calculator was continuously developed and appeared in 1968 under the name Nixdorf 820 after Nixdorf took over Wanderer-Werke.

With this not freely programmable small computer, NCAG opened up a new market: medium-sized data technology , especially for small and medium-sized companies . The system family 820, meanwhile distributed through the branch network of Wanderer-Werke, was a great economic success and paved the way for NCAG to become the fourth largest computer manufacturer in Europe.

Technical details

Base

Nixdorf 820 from 1968

The main technical components of the Nixdorf 820 system (built in 1968) were

In addition to the writing mechanism, a cassette recorder can also be seen in the photo , which was used to digitally store data in a frequency-modulated manner.

The magnetic core memory, internally referred to as living (end) memory, was usually only used to hold user programs during development. Once the program was tested, it was "threaded" on the plug-in module for the stick memory (internally referred to as permanent memory). Subsequent corrections and extensions were therefore very difficult to handle by making a "program jump" internally to an unused memory area, installing the desired program sequence there, and then jumping back to the original program sequence, and of course by skipping the faulty code. This method was known as a "backpack". Since there was a separation of program and data memory, the 820 was based on a Harvard architecture . In contrast to Von Neumann computers, it was therefore not “freely programmable”. The non-volatile memory used, however, had the advantage that the computer was ready for use immediately after switching on and no programs had to be loaded.

Periphery

Punched card readers / punches, tape readers / punches, punched tape card readers and magnetic accounts were available for data input and output .

literature

  • Christian Berg: Heinz Nixdorf. A biography, (studies and sources on Westphalian history, vol. 82), Schoeningh , Paderborn / Munich / Vienna / Zurich 2016, ISBN 978-3-506-78227-4 .
  • Klaus Kemper: Heinz Nixdorf - a German career . Verlag Moderne Industrie, 1986, ISBN 3-478-30120-3

Web links

Individual evidence

  1. ↑ Dipl. Phys. H. Müller: "Early commercial computers" in the "technikum29" museum
  2. ↑ Dipl. Phys. H. Müller: "Nixdorf 820 console with magnetic account attachment, two Forster branded punch card readers" In the "technikum29" museum
  3. ↑ Dipl. Phys. H. Müller: "Threaded ROM, read-only memory" in the "technikum29" museum